Brutaldon is a brutalist web client for Mastodon and Pleroma. It supports text-mode browsers such as Lynx and w3m, as well as older graphical browsers. Newer graphical browsers such as Firefox are supported with progressive enhancement.
At this point, it is largely complete — the features it does not have are also not planned. It is possible to use it as your primary interface for reading and posting on the fediverse.
There is a live instance you can use at brutaldon.online. It has a GitHub page, though I am planning on eventually moving it to a self-hosted repository.
There is a blog post about writing it at my blog.